Electrophotographic printing involves applying a uniform surface charge to a photoconductor and exposing the photoconductor to imaging light in select areas to define a latent electrostatic image on the photoconductor. The latent image is developed by depositing toner particles on the surface of the photoconductor. The toner adheres to the imaged areas of the photoconductor to form a developed image that is transferred to paper or another imaging media. The loose toner is then fused to the paper by passing the paper between a heated fuser roller that contacts the top of the paper and an opposing pressure roller that contacts the bottom of the paper. Over time, toner builds up on the pressure roller. Toner build-up on the pressure roller must be cleaned periodically to maintain good print quality.
In the past, cleaning pads were used to clean toner build-up on the pressure roller. Cleaning pads are oil impregnated pads or fabric webs that contact the heated fuser roller to wipe away residual toner before the toner has a chance to deposit on the pressure roller. Cleaning pads have been largely eliminated from laser printers and other electrophotographic printing devices for both ecological and usability reasons. Cleaning pads have to be replaced each time the print cartridge is replaced. Eliminating cleaning pad replacement made it easier to replace the print cartridge. Cleaning pads require additional manufacturing materials--plastic substrate, fabric pad and lubricating oil--that often end up in a landfill. Since the elimination of cleaning pads, the build-up of toner on the fuser pressure rollers has become more of a problem. Newer self cleaning fuser designs have attempted to minimize toner build-up, but periodic cleaning is sometimes still necessary to maintain good print quality. The adverse effects of toner build-up on the pressure roller have become an increasingly important problem in those parts of the world where paper with high calcium carbonate content is used.
One solution to toner build-up in modern printing devices is the use of a cleaning page. Presently, the user must generate the cleaning page from the printer's front panel or by printing an appropriate image from the host. The cleaning page typically includes a wide diagonal bar printed across the width of the page along with text instructing the user to place the cleaning page back in the paper tray upside down and print the page again. When the cleaning page is fed into the printer the second time, it goes through the printer with the printed side down. As it passes through the fuser, the toner that makes up the diagonal stripe becomes tacky. The tacky toner cleans the pressure roller as the roller comes in contact with the printed side of the page. This manual process is inconvenient at best, and customers, particularly in network environments, either do not know how to or do not want to go through the effort of generating and processing the cleaning page.